The primary objective of this study is to determine the safety and immunogenicity of an improved two-vial formulation of CHO cell-derived HIV-1 SF-2 rgp120 envelope vaccine formulated with MF59 adjuvant emulsion when administered to healthy HIV-1 uninfected volunteers. Prior formulations had suboptimal ability or were impractical (requiring storage at -70oC). Therefore, an improved formulation has been developed that is expected to be more practical and stable, to allow studies of this expanded vaccine candidate or analogous candidates designed for other geographic regions. Secondarily, this improved two-vial formulation will be used in AVEGProtocol 022 as a boost after priming with a live canarypox vector vaccine. AVEGProtocol 024 will be conducted concurrently with AVEG 022 and, therefore, will serve as the rgp120/MF59 alone control group for AVEG Protocol 022.